1    :  // Copyright 2014 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  
  15    :  #include "syzygy/agent/asan/block_utils.h"
  16    :  
  17    :  #include "gtest/gtest.h"
  18    :  #include "syzygy/agent/asan/logger.h"
  19    :  #include "syzygy/agent/asan/unittest_util.h"
  20    :  
  21    :  namespace agent {
  22    :  namespace asan {
  23    :  
  24    :  namespace {
  25    :  
  26    :  typedef testing::TestWithAsanRuntime BlockUtilTest;
  27    :  
  28    :  }  // namespace
  29    :  
  30  E :  TEST_F(BlockUtilTest, IsBlockCorruptInvalidMagicNumber) {
  31  E :    const size_t kAllocSize = 100;
  32    :    testing::FakeAsanBlock fake_block(
  33  E :        runtime_->shadow(), kShadowRatioLog, runtime_->stack_cache());
  34  E :    EXPECT_TRUE(fake_block.InitializeBlock(kAllocSize));
  35    :  
  36    :    fake_block.block_info.header->magic =
  37  E :        static_cast<unsigned>(~kBlockHeaderMagic);
  38  E :    EXPECT_TRUE(IsBlockCorrupt(fake_block.block_info));
  39  E :    fake_block.block_info.header->magic = kBlockHeaderMagic;
  40  E :    EXPECT_FALSE(IsBlockCorrupt(fake_block.block_info));
  41  E :  }
  42    :  
  43  E :  TEST_F(BlockUtilTest, IsBlockCorruptInvalidChecksum) {
  44  E :    const size_t kAllocSize = 100;
  45    :    static const size_t kChecksumRepeatCount = 10;
  46    :  
  47    :    // This can fail because of a checksum collision. However, we run it a
  48    :    // handful of times to keep the chances as small as possible.
  49  E :    for (size_t i = 0; i < kChecksumRepeatCount; ++i) {
  50    :      testing::FakeAsanBlock fake_block(
  51  E :          runtime_->shadow(), kShadowRatioLog, runtime_->stack_cache());
  52  E :      EXPECT_TRUE(fake_block.InitializeBlock(kAllocSize));
  53  E :      EXPECT_TRUE(fake_block.MarkBlockAsQuarantined());
  54    :  
  55    :      // Change some of the block content and verify that the block is now being
  56    :      // seen as corrupt.
  57  E :      uint8 original_value = fake_block.block_info.RawBody(0);
  58  E :      fake_block.block_info.RawBody(0)++;
  59    :  
  60    :      // Try again for all but the last attempt if this appears to have failed.
  61    :      if (!IsBlockCorrupt(fake_block.block_info) &&
  62  E :          i + 1 < kChecksumRepeatCount) {
  63  i :        continue;
  64    :      }
  65    :  
  66  E :      ASSERT_TRUE(IsBlockCorrupt(fake_block.block_info));
  67  E :      fake_block.block_info.RawBody(0) = original_value;
  68  E :      ASSERT_FALSE(IsBlockCorrupt(fake_block.block_info));
  69  E :      break;
  70  i :    }
  71  E :  }
  72    :  
  73  E :  TEST_F(BlockUtilTest, IsBlockCorruptInvalidFloodFilledBody) {
  74  E :    const size_t kAllocSize = 100;
  75    :  
  76    :    testing::FakeAsanBlock fake_block(
  77  E :        runtime_->shadow(), kShadowRatioLog, runtime_->stack_cache());
  78  E :    EXPECT_TRUE(fake_block.InitializeBlock(kAllocSize));
  79  E :    EXPECT_TRUE(fake_block.MarkBlockAsQuarantined());
  80  E :    fake_block.block_info.header->state = QUARANTINED_FLOODED_BLOCK;
  81    :    ::memset(fake_block.block_info.RawBody(),
  82    :             kBlockFloodFillByte,
  83  E :             fake_block.block_info.body_size);
  84  E :    BlockSetChecksum(fake_block.block_info);
  85  E :    ASSERT_FALSE(IsBlockCorrupt(fake_block.block_info));
  86    :  
  87  E :    fake_block.block_info.RawBody(1) ^= 0x3C;
  88  E :    ASSERT_TRUE(IsBlockCorrupt(fake_block.block_info));
  89  E :  }
  90    :  
  91    :  }  // namespace asan
  92    :  }  // namespace agent